1978 年 98 巻 6 号 p. 794-801
The degree of swelling of bovine eye-lens capsule was measured in solutions of various pH and ionic strength, and the effect of swelling on the membrane permeability was examined. It was found that, when ionic strength of solution was low, capsule swelled both in a more acidic region than the isoelectric point and in a more alkaline region than the isoionic point of collagen, which is the main component of the capsule. The swelling is, therefore, due to repulsion among electric charges of the collagen. The void ratio, the apparent membrane constant, and the membrane permeability of capsule increased in propotion to swelling of the capsule. On the other hand, when ionic strength of the solution was high, the capsule was dehydrated and shrank. Because of the decrease of free water in the capsule by dehydration, the membrane permeability decreased and, in the case of an electrolyte, the transport number was affected in the manner that the transport number of a cation increased and that of an anion decreased. This resulted because the frictional resistance of the matrix of dehydrated capsule was smaller for cations than for anions since the radius of cations was smaller than that of anions.